Electrode for luminous tubes



Nov. 17, 1931. A, E. JACOBSEN ELECTRODE FOR LUMINOUS TUBES Filed Oct. 20, 1928 INVENTOR ATTORNEY PatentedNov. 17, 1931 NITEDI STATES PATENT OFFICE ALBERT EDWIN JACOBSEN, OF SEATTLE, WASHINGTON, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, T0 NEON SPECIALTY 8: MANUFACTURING 00., A CORPO- RATION ELECTRODE FOR LUMINOUS TUBES 2 i Application filed October 20, 1928. Serial No. 313,855.

This invention relates to an improved electrode for use in systems of illuminating by luminous glass tubes-that have been more or less evacuated and into which various gases or chemicals have been introduced as a means of producing lights of various colors incident to the passing of an electric current through the tubes.

As a matter of explanation, it will be here stated that in lighting systems of the above character, glass tubes with enlarged opposite end portions are employed, and electrodes for passing the circuit through the tubes are'atfixed in or applied to the enlarged end portions. Heretotore, the electrodes employed for passing the electric current into and from the tube have made electrical contact from the outside to the inside of the glass tube by metallic connections that are sealed or cemented in or to the glass. This form of contact, or connection, has proven to be not altogether satisfactory owing to possible and frequent leakage along the sealedin metallic connecting wire or cemented-on metallic portion of the electrode, resulting from an unequal expansion or contraction of the connecting element and glass incident to temperature changes.

In view of the above, it has been the principal object of the present invent on to overcome this undesirable result by the provison of luminous tubes of the above character, wherein no metallic or wire conductor is sealed in or extended through the glasstube, or wherein any direct metallic connect on is made which may actas an electric conductor from the source of electricity to the gases within the-tube.

A further object of the invention resides in the provision of an efi'ective and durable electrode and/terminal member associated therewith. which is of simple construction, rela tivelv inexpensive and not subject to becominn inactive through leakage or breakage.

More specifically, the object of the invention resides in the provision of an electrode consisting of a metallic cap, tube, film or coating adapted to be fitted about a terminal of the glass tube and which serves as one plate of a condenser for capacitatively connecting the circuit with the contained gas in the tube which, by itself, or in combination with other supplementing parts, serves as the other plate of the condenser.

Other objects of the invention reside in the various details of construction and in the combination of parts and in their use, as is hereinafter described.

In accomplishing these objects, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanyingdrawings, wherein- Figure 1 is a view illustrating the construction, application and use of electrodes embodied by the present invention as applied to the opposite ends of a luminous, glass tube; one terminal of the tube and its electrode being shown in longitudinal section for better illustration.

Figure 2 is a cross section taken onthe line 22 in Figure 1.

Referring more in detail to the drawings 1 designates a glass tube of that character used in illuminating systems of the above mentioned type and which is provided at its opposite ends with bulb-like enlargements 2-2 inopen communication with the tube; the tube andenlargements being sealed after being more or less evacuated and after the introduction thereinto of suitable gas, gases or chemicals for producing the path for the electric current and the desired colored lighting efl'ects when an electric current is passed through the tube. The bulb-like ter-.

7 minal enlargements of the tube are of cycasing 3, or a coating, or even a film of a suitable metallic quality, for conducting the electric current and which is fitted about 'or I applied over the bulb-like enlargement 2 at one end of the tube. As here shown, the member 3 is in the form of a metallic sleeve that fits snugly about the cylindrical body portion of the terminal and is'closed at' its outer endby a semi-spherical end portion 3a that fits snugly about the semi-spherical end of the bulb and from which a metallic terminal member 4 extends; the terminals l ofthe two members 3 being of a suitable Character for the connection thereto of circuit wires 5 -5 which lead, respectively, from and toa source of low frequency, referably 60'cycle alternating high voltage e ectric current.

Applied'to or fitted within the bulb-likeportion of the tube and directly within the outer sleeve-like portions 3, is a metallic film, coating or lining 6 and in addition thereto there is disposed co-axially within the bulb-like portion of the tube and within the sleeve-like molecules of the rarefied gases.

'7 portion 6, a metallic, tubular element 7 supported in spaced relation from the lining sleeve 6 by means of a plurality of insulating balls 8 which are set within openings '9- formed in the tube about the opposite end portions.

It will be readily apparent that the. electrical connection between the outside portions 3 'of the electrodes and the inside included gases is made by thus capacitatively connecting the outside of the electrode with the inside, using the outside metallic tube 3 asfone plate of a condenser and the contained gasin the tube, by itself, or supplemented by the sleeve-like element 6, or in combination withf the tube 7, as the other plate of a condenser while the glass bulb itself serves as the dielectric separator or insulator between the condenser plates; the path of the electric current flowing from the source of low frequency alternating high voltage electric current through the wire 5 to the electrode contact terminal 4, thence to. theoutside condenser element ,3. thence to sleeve 6 and tube 7 or connecting directly with the included, inclosed gases in the tube, thence following the gases to the the tube. and the effective electric action is in line with the movement of the polarized There is no breaking down of the glass, or the gases, even though they are not of the noble group and no perceptable heatwill be generated. Furthermore, sufiicient amount of light will not pass from the tube to disturb surrounding lighting efiects, nor will the light from the tubes blend together even though tubes are of small size and placed closely together.

However, ample light or glow will be produced for the purpose intended, and the amount of current used will be very small in comparison with other types or systems of lighting.

It will be here stated that while in some instances the inside elements 6 and 7 are not essential, they are in all instances desirable and in most instances essential. In any event, they aid materially in the condenser action of the electrodes and add to the efiiciency of the electrode as a whole.

Having thus described my invention, what I claim as new therein and desire to scour by Letters-Patent, is: 1. An electrode for luminous'tubes of the character described, consisting of a metallic cap, or sleeve, applied about a terminal portion of a luminous tube and havingprovision forv connection with one side of an electric circuit, a metallic lining member fitted to the inner surface of-said terminal portion of the tube directly within the outer sleeve or cap, a metallic tube disposed within the said lining, and non-conductive elements supporting said gube in spaced relation from said lining mem- 2. An electrode for luminous tubes of the character described, comprising inner and outer metallic, conductive elements applied, respectively, to and about the inner and outer surfaces of a terminal portion of a luminous tube, a metallic, conductive tube disposed within the said conductive elements and having a plurality of small openings therein, and insulating supporting members seated within said openings and engaging with the said inner conductive element.

3. A luminous tube of the character described having a bulb-like terminal portion formed with a cylindrical body and a semispherical end wall with an electrode comprising conductive elements fitted respectively to the outer and inner surfaces of the said termin al portion of the tube to cover the surfaces of the cylindrical body and semi-spherical end wall, and having no metallic connection between the said elements and thus capacitatively serving as inner and'outer plates of a condenser, while the terminal portion of the tube serves as the dielectric separator therefor; the outer conductive element being adapted for connecting with an electric circuit of low frequencies.

4. A luminous tube of the character described having a bulb-like terminal portion formed with a cylindrical body, and a semispherica-l end wall with an electrode consisting of outer and inner conductive elements fitted respectively to the outer and inner surfaces of the terminal portion to cover the en- I aaaaaia tire body portion and end wall surfaces, metallic tubular elements supported in spaced 7 relation within the said inner element; said outer conductiveelement having terminals for connection with one side of an electric circuit of low frequencies, and said element serving as one plate of a condenser, the inner conductive element and the metallic tube as the other plate of a condenser, while the tera minal portion of the tube serves as the dielectrio separator for'said plates. L

Signed at Seattle, Washington, this 28th day ofSeptember, 1928.

ALBERT EDWIN JACOBSEN, 

